Recently, the semiconductor micromachining technology such as the photolithography technique, the thin film deposition technique, and the etching technique, which are performed mainly on silicon substrates, has been employed to manufacture a microstructure into which composite functions such as mechanical, electronic, optical, and chemical ones are integrated. The aforementioned microstructure is called a Micro Electro Mechanical Systems (MEMS) device, which is applied, for example, to actuators, pressure sensors, temperature sensors, acceleration sensors, and angular acceleration sensors. These MEMS devices have, as an essential elemental member, thin film of the order of submicrons to microns formed on a substrate. The thin film of the order of submicrons to microns may be different in material properties from bulk material, and thus the thin film material needs to be directly evaluated concerning the mechanical properties (such as the modulus of elasticity, strength, rupture toughness, and fatigue property). In this context, for evaluation of the mechanical properties, for example, a micromaterial strain measurement apparatus has been suggested as disclosed in Patent Literature 1.
Disclosed in Patent Literature 1 is that the deformation of micromaterial resulting from tensile stress or compressive stress is to be measured by a scanning probe microscope. More specifically, the micro deformation can be measured by providing the surface of the micromaterial with a minute grid line pattern serving as a gauge point and then measuring a change in the gauge point with the scanning probe microscope.